Lecture 23: Transport in Vascular Plants Flashcards
how does water climb trees?
capillary action
transpiration
root presure
what does capillary action use to work?
secondary xylem (tracheids/vessel elements), thin tube = greater length of transport!
how does transpiration work?
water potential
strength of water column
through leaves and canopy!
how does root pressure work to allow water to climb trees?
water enters roots via osmosis
what are the three transport routes for water/solutes? where do they go?
- apoplastic route (through cell wall)
- symplastic route (through cytosol: within cell)
- transmembrane route (across cell wall and plasma membrane)
how does water potential work?
high water potential (negative) to low water potential (VERY negative)
_____ determines the direction of water movement and the water’s capacity to do work
water potential
when osmosis occurs in a flaccid plant…
plant gains water and becomes turgid
turgor loss in plants results in ____
wilting
changes in turgor pressure opens/closes the _____
stomata
when plant is turgid, stomata….
opens pore as guard cells bow outwards
when a plant is flaccid, stomata…
closes pore
how are guard cells controlled?
with potassium
____ is needed for efficient long-distance transport
bulk flow
the ____ is the last checkpoint for passage of minerals into vascular tissue
endodermis
the ____ is waxy and made of _____… it blocks the apoplastic transfer of minerals within plant cells
casparian strip, suberin
_____ is the evaporation of water from a plant’s surface
transpiration
____ of water creates negative pressure potential
surface tension
what is the path of water uptake to adhesion/cohesion in xylem, to transpiration of water?
soil - roots - cohesion/adhesion in xylem - end of xylem in leaves - mesophyll - intercellular spaces in between spongy mesophyll - stomata - atmosphere
____ is when products of photosynthesis are transported through phloem
translocation
the path of translocation is from a ____ to a _____
sugar source to sugar sink
____ is an aqueous solution, high in sucrose
phloem sap
a ____ is where sugars are made
sugar source
where are sugars made in plants?
chloroplasts in leaves!
a ____ is where sugars end up
sugar sink (fruits/seeds/roots)
why do we need sugar sinks?
because not every area of the plant can photosynthesize and make its own sugars
